All that has happened over the last week at the National Solar Observatory in Sunspot, in the US state of New Mexico, 130 miles southwest of Roswell—and the situation is still a mystery.

It seems to have started last Friday when the observatory was temporarily closed because of an undisclosed security issue. Shari Lifson, a spokesperson for the group that manages the facility—Association of Universities for Research in Astronomy (AURA)—told the Alamogordo Daily News: “We have decided to vacate the facility at this time as a precautionary measure. It was our decision to evacuate the facility.”

Otero County Sheriff Benny House told the Daily News that FBI agents told his officers to “standby,” and would not explain the security threat to him or why the federal law enforcement agency was involved. “But for the FBI to get involved that quick and be so secretive about it, there was a lot of stuff going on up there,” House said to the Daily News. “There was a Blackhawk helicopter, a bunch of people around antennas and work crews on towers, but nobody would tell us anything.”

House seemed especially confused since the staff at the observatory aren’t federal employees, as far as he knows. “These guys are regular workers that work for this company. I don’t know why the FBI would get involved so quick and not tell us anything,” he told the Daily News.

Frank Fisher, a public affairs officer at FBI’s Albuquerque Division, told Gizmodo that it was referring all inquiries to AURA. Lifson of AURA told Gizmodo today that the facility is still closed because the research group is still “addressing a security issue” and “is working with the proper authorities on this issue,” but has no further comment about the nature of the security issue.

A dispatcher at the Otero County Sheriff’s office told Gizmodo that the matter is still a complete mystery to their office. “We don’t know what is going on. We haven’t had any updates. We haven’t gotten any information at all,” he said. “There’s not much we can do about it. We’ve decided to respect their wishes. We’re not going to make any inquiries and they’re not telling us.” [Alamogordo Daily News]